Shaped trilobal particles

ABSTRACT

An elongate, shaped particle having three protrusions each extending from and attached to a central position aligned along the central longitudinal axis of the particle, the cross-section of the particle occupying the area encompassed by the outer edges of six outer circles around a central circle minus the area occupied by three alternating outer circles, wherein each of the six outer circles is touching two neighbouring outer circles and wherein three alternating outer circles are equidistant to the central circle, have the same diameter, and may be attached to the central circle.

FIELD OF THE INVENTION

The present invention relates to formed particles having a specificshape which particles may be employed in a wide variety of duties,catalytic or non-catalytic. They can be suitably applied to prevent orsubstantially reduce fouling of catalyst beds exposed to chargescontaining fouling material, thereby reducing increases in pressuredrop. They can also be applied in hydroprocessing, e.g. inhydrodesulphurisation and hydrocracking, e.g. to produce middledistillates from paraffinic material obtained via a Fischer-Tropschprocess.

BACKGROUND OF THE INVENTION

In the past a tremendous amount of work has been devoted to thedevelopment of particles, in particular catalytically active particles,for many different processes. There has also been a considerable effortto try to understand the advantages and sometimes disadvantages ofeffects of shape when deviating from conventional shapes such aspellets, rods, spheres and cylinders for use in catalytic as well asnon-catalytic duties.

Examples of further well-known shapes are rings, cloverleafs, dumbellsand C-shaped particles. Considerable efforts have been devoted to theso-called “polylobal”-shaped particles. Many commercial catalysts areavailable in TL (Trilobe) or QL (Quadrulobe) form. They serve asalternatives to the conventional cylindrical shape and often provideadvantages because of their increased surface-to-volume ratio whichenables the exposure of more catalytic sites thus providing more activecatalysts.

An example of a study directed to effects of different shapes oncatalytic performance can be found in the article by I. Naka and A. deBruijn (J. Japan Petrol. Inst., Vol. 23, No. 4, 1980, pages 268–273),entitled “Hydrodesulphurisation Activity of Catalysts withNon-Cylindrical Shape”. In this article experiments have been describedin which non-cylindrical extrudates with cross-sections of symmetricalquadrulobes, asymmetrical quadrulobes and trilobes as well ascylindrical extrudates with nominal diameters of 1/32, 1/16 and 1/12inch were tested in a small bench scale unit on theirhydrodesulphurisation activity (12% wt MoO₃ and 4% wt CoO on gammaalumina). It is concluded in this article that the HDS activity isstrongly correlated with the geometrical volume-to-surface ratio of thecatalyst particles but independent of catalyst shape.

In EP-A-220933, published in 1987, it is described that the shape ofquadrulobe-type catalysts is important, in particular with respect to aphenomenon known as pressure drop. From the experimental evidenceprovided it appears that asymmetric quadrulobes suffer less frompressure drop than the closely related symmetrical quadrulobes. Theasymmetrically shaped particles are described in EP-A-220933 by way ofeach pair of protrusions being separated by a channel which is narrowerthan the protrusions to prevent entry thereinto by the protrusions of anadjacent particle. It is taught in EP-A-220933 that the shape of theparticles prevents them from “packing” in a bed causing the overall bulkdensity of the catalyst bed to be low.

Since many of the findings in the art are conflicting and pressure dropproblems continue to be in existence, especially when surface-to-volumeratios are increased by reducing particle size, there is stillconsiderable room to search for alternative shapes of (optionallycatalytically active) particles which would diminish or even preventsuch problems. It has now surprisingly been found that specificallyshaped particles of the general “trilobal” shape offer unexpected andsizeable advantages compared with conventional “trilobal” particles,both in catalytic and non-catalytic duty.

SUMMARY OF THE INVENTION

The present invention therefore relates to an elongate, shaped particlecomprising three protrusions each extending from and attached to acentral position aligned along the central longitudinal axis of theparticle, the cross-section of the particle occupying the areaencompassed by the outer edges of six outer circles around a centralcircle minus the area occupied by three alternating outer circles,wherein each of the six outer circles is touching two neighbouring outercircles and wherein three alternating outer circles are equidistant tothe central circle, have the same diameter, and may be attached to thecentral circle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a cross-sectional view of the most preferred particles accordingto the invention has been depicted.

It has been found that the particles according to the present invention,having a larger surface-to-volume ratio than corresponding conventional“trilobal” particles of similar size, suffer substantially less frompressure drop than such corresponding conventional “trilobal” particles.Moreover, the shape of the particles according to the present inventionallows a certain degree of “packing” which according to the teaching ofEP-A-220993 would be detrimental with respect to pressure drop.

It has also been found that particles having a shape in accordance withthe present invention perform exceptionally well when used as a gradingmaterial to capture fouling, thereby guarding a fixed-bed reactoragainst pressure drop increase. It is also believed that catalysts basedon particles in a shape according to the present invention are capableof improved performance when used in mass transfer or diffusion limitedreactions in fixed-bed reactors, for instance as hydrocracking catalystsin the hydrocracking of paraffinic materials produced from synthesis gasvia the Fischer-Tropsch process.

The particles according to the invention are elongate and have threeprotrusions, each running along the entire length of the particle. Thecross-section of the particles can be described as the area encompassedby the outer edges of six circles around a central circle minus the areaoccupied by three alternating outer circles.

Each of the six outer circles is touching two neighbouring outer circlesand does not overlap with the two neighbouring outer circles. The sixouter circles can be seen as two sets of alternating outer circles, i.e.the three alternating outer circles that are within the cross-sectionalarea and the remaining three alternating outer circles. The threealternating circles are equidistant to the central circle, have the samediameter, and may be attached to the central circle. The distance to thecentral circle and the diameter of the circles may be different for bothsets of alternating outer circles.

Preferred particles according to the present invention have across-section in which three alternating circles have a diameter in therange between 0.74 and 1.3 times the diameter of the central circle.Preferably, all six outer circles have a diameter in this range.

More preferred particles according to the present invention are thosehaving a cross-section in which three alternating circles have the samediameter as the central circle. Preferably, all six outer circles havethe same diameter as the central circle.

Most preference is given to particles having a cross-section in whichthree alternating circles are touching the central circle. Preferably,all six outer circles are touching the central circle.

In FIG. 1 a cross-sectional view of the most preferred particlesaccording to the invention has been depicted. The cross-sectional areaof the particle of FIG. 1 is the area within the solid line 1. It willbe clear from this Figure (depicting the cross-section of the preferredparticles) that in the concept of six outer circles of even size alignedaround a central circle of the same size, each outer circle touches itstwo neighbour outer circles and the central circle whilst subtraction ofthree alternating outer circles (dotted line 2) provides the remainingcross-sectional area, built up from four circles (the central circle andthe three remaining alternating outer circles) together with the sixareas (3) formed by the inclusions of the central circle and six timestwo adjacent outer circles. The nominal diameter for the preferredparticles is indicated as d nom in FIG. 1.

The cross-sectional circumference of the particles according to thepresent invention is such that it forms a smooth line, which can also beexpressed as the function describing the cross-sectional circumferencebeing continuously differentiable.

It will be clear that minor deviations from the shape as defined areconsidered to be within the scope of the present invention. It is knownto those skilled in the art to manufacture die-plates which tolerancescan be expected in practice when producing such die-plates.

It is possible to produce particles according to the present inventionwhich also contain one or more holes along the length of the particles.For instance, the particles can contain one or more holes in the areaformed by the central cylinder (the central circle in the cross-sectiongiven in FIG. 1) and/or one or more holes in one or more of thealternating cylinders (the alternating outer circles in thecross-section given in FIG. 1). The presence of one or a number of holescauses an increase of the surface-to-volume ratio which in principleallows exposure of more catalytic sites and, in any case, more exposureto incoming charges which may work advantageously from a catalyticand/or fouling rejection point of view. Since it becomes increasinglydifficult to produce hollow particles as their size becomes smaller, itis preferred to use massive particles (still having their micropores)when smaller sizes are desired for certain purposes.

It has been found that the voidage of the particles according to thepresent invention is well above 50% (voidance being defined as thevolume fraction of the open space present in a bed of particles outsidethe particles present, i.e. the volume of the pores inside the particlesare not included in the voidage). The particles used in the experimentto be described hereinafter had a voidage of typically 58% which issubstantially above that of the comparative “trilobal” particle, thevoidage of which amounted to just over 43%.

The particles according to the present invention can be described ashaving a length/diameter ratio (L/D) of at least 2. The diameter of theparticles is defined as the distance between the tangent line thattouches two protrusions and a line parallel to this tangent line, thattouches the third protrusion. It is indicated as d nom in FIG. 1.Preferably, the particles according to the present invention have a L/Din the range between 2 and 5. For example, the particles used in theexperiment to be described hereinafter had a L/D of about 2.5.

The length of the particles in accordance with the present invention issuitably in the range between 1 and 25 mm, preferably in the rangebetween 3 and 20 mm, depending on the type of application envisaged. Foruse in fouling control and in hydrodesulphurisation particles canconveniently be used which have a diameter in the range between 2 and 5mm.

The shaped particles can be formed of any suitable material provided itis capable of being processed through die-plates giving them theirintended shape. Preference is given to porous materials which can beused in catalytic as well as in non-catalytic applications. Examples ofsuitable materials are inorganic refractory oxides such as alumina,silica, silica-alumina, magnesia, titania, zirconia and mixtures of twoor more of such materials. The choice of the material will normallydepend on the envisaged application. It is also possible to usesynthetic or natural zeolites, or mixtures thereof, optionally togetherwith one or more of the refractory oxides referred to hereinabove, asthe material(s) to be used to form the shaped particles according to thepresent invention. Good results can be obtained with (catalyticallyactive) particles based on alumina, in particular with gamma-alumina,and various forms of silica-alumina, but other materials can also beapplied satisfactorily.

In the event that the particles according to the invention are to beused in catalytic processes, the appropriate amount(s) of catalyticallyactive metal(s) and/or metal compound(s) will have to be present on theparticles, which then serve as catalyst carrier (in addition to theircapacity to abate fouling as the case may be). Those skilled in the artknow which metal(s) and/or metal compound(s) to apply for specificapplications and also to which extent and how to incorporate the chosenmoieties on the particles envisaged.

When, for instance, hydrodesulphurisation of hydrocarbonaceousfeedstocks is envisaged, the shaped particles according to the presentinvention will normally contain one or more metal(s) of Group VI and/orone or more non-noble metal(s) of Group VIII of the Periodic Table ofthe Elements which are conveniently present as oxides and/or assulphides. When the expression “hydrodesulphurisation” is usedthroughout this specification it also includes hydrodenitrogenation andhydrogenation as these hydrotreating processes normally take place atthe same time. Hydrodesulphurisation conditions normally comprise atemperature in the range between 150 and 400 degrees centigrade, ahydrogen partial pressure up to 80 bar and a LHSV in the range between 1and 20 Nl feed/l catalyst/hr. The H₂/hydrocarbon feed ratio is suitablyin the range from 100 to 2000 Nl/l.

The particles according to the present invention can be usedadvantageously in guard bed duty. Guard beds are normally applied toprotect other catalytic beds downstream of the guard bed againstunwanted influences caused by the feedstream to be processed over suchcatalytic beds.

Fouling is one of the most encountered problems when processingfeedstocks through one or more catalytic beds. The fouling observed canbe caused by impurities in the feedstock which were either presentalready or which may have been formed during the process. Examples ofimpurities present in the feedstock to be treated are, for instance,metal-containing particles and/or clay or salt particles which had notor had only been removed incompletely prior to processing over theappropriate catalytic bed(s). Examples of impurities formed duringprocessing are, for instance, fragments of catalytic active particleswhich were removed from the catalytic bed(s) which in recycle operationare passed through such catalytic bed(s) or coke particles formed duringexposure of the feedstock to (severe) process conditions.

Guard beds are normally placed upstream of the bed(s) used in thecatalytic process. One or more guard beds can be used to absorb theimpurities, thereby delaying the occurrence of pressure drop whichallows a longer on stream time of the process envisaged. It is alsopossible to provide part or all of the particles forming the guard bedwith catalytically active materials, thereby combining guard andreaction duty. It is also possible to incorporate catalytically activematerial of a different nature than that used in the process asenvisaged in the particles of the guard bed. For instance, materialsactive in hydrotreating may be present in and/or on the particlesforming the guard bed(s) having the duty to protect one or more catalystbeds used in hydrocracking and placed downstream of the guard bed. Thetype and amount of catalytically active materials present in such guardbeds are well known in the art and those skilled in the art know how toemploy them.

Specific applications for the particles according to the presentinvention are as grading layers to protect fixed-bed reactors prone toheavy (feedstock originating) fouling which may occur inhydroconversion, in particular in hydrodemetallisation processes, longresidue hydrodesulphurisation processes and in the processing ofthermally cracked material and to protect fixed-bed reactors sufferingfrom fines deposition deep in the catalytic beds, for instance in unitsprocessing synthetic crudes.

It has been found that the beds containing particles according to theinvention have—in a random packing—a much higher voidage than bedscontaining the corresponding conventional trilobes when packed using thewell known “sock loading” technique. The voidage obtained when using theconventional trilobal shape amounts to about 45% whereas use of theparticles according to the present invention produces a voidage of atleast 55% which makes such particles attractive for low pressure dropapplications, for instance under conditions of countercurrent gas-liquidflow.

The particles according to the present invention can also be suitablyapplied in a process for the production of middle distillates fromsynthesis gas in which heavy paraffinic material produced from carbonmonoxide and hydrogen is subjected to a hydrocracking process to producemiddle distillates in the presence of a catalyst containing particlesaccording to the present invention which also contain one or moremetals(s) and/or metal compound(s) possessing the desired catalyticactivity.

The invention will now be illustrated by means of the followingnon-limiting examples.

EXAMPLE 1

Two model experiments were carried out to monitor the pressure dropunder fouling conditions of catalyst particles made up of conventionaltrilobes (to be referred to hereinafter as TL) and of particles having ashape as shown in FIG. 1 (to be referred to hereinafter as STL—“special”trilobes, having a cross-section occupying the area inside seven circlesof the same size (the central circle attached by six outer circles ofthe same size and three alternating outer circles forming part of thecross-section) minus the three remaining outer circles).

The TL particles had a nominal diameter of 2.5 mm, an L/D of about 2.5,and were made of gamma alumina. A randomly packed bed of the TLparticles showed a voidage of 43%. They did not contain additionalcatalytic material. The STL particles had a nominal diameter of 2.8 mm,an L/D of about 2.5, and consisted of material normally used for DN-200catalysts (commercially available from Criterion Catalyst Company). Arandomly packed bed of the STL particles showed a voidage of 58.3%. Bothtypes of particles were obtained by extrusion using an appropriate dieplate.

The fouling material used in the two experiments consisted of a mixtureof crushed silica and FCC (Fluid Catalytic Cracking) catalyst. Thecomposition of the fouling material is given in Table 1 below.

TABLE 1 Size (nm) Fraction (% w/w) Type of material  1.4–1.7 0.58 silica 1.18–1.4 0.71 silica  0.6–1.18 6.60 silica 0.355–0.6 4.51 silica0.212–0.355 4.85 silica 0.125–0.212 7.01 silica <0.125 75.74 FCC cat.

The experiments were carried out in a single column containing thematerial to be tested. The column was operated with cocurrent gas (air)and liquid (water) flow at ambient temperature and pressure. Gas andliquid superficial velocities were 100 mm/s and 4 mm/s, respectively.Before each experiment, the packing was properly wetted with cleanwater.

The experiments started by switching the liquid feed from clean water toa slurry containing 2.94 kg.m³ of the fouling material. Thisconcentration is several orders of magnitude higher than that to beexpected under normal operating conditions in order to be able to assessthe phenomenon of pressure drop within a relatively short time. It wasfound that the run time for the TL particles (before a pressure drop of500 mBar/m was observed) amounted to 1460 seconds whereas the use of STLparticles allowed for a run time of no less than 2260 seconds, i.e. a55% increase compared to the conventionally shaped particles.

EXAMPLE 2

Two experiments were carried out to compare flooding limits occurringwhen using conventional TL and particles having a shape according to thepresent invention (in this case, as shown in FIG. 1). The particles usedin these experiments had the same shapes and compositions as thosedescribed in Example 1. A randomly packed bed of the TL particles showeda voidage of 40% and that of STL particles showed a voidage of 55%.

The experiments were carried out in a single column operatedcountercurrently with n-octane and nitrogen at ambient temperature and 2bar absolute pressure. Care was taken to ensure uniform gas and liquiddistribution. During the experiments, gas flow was increased at aconstant liquid flow rate and pressure drop was measured across thecolumn. The flood point is defined as the point where the pressure dropdependence on the gas velocity abruptly changes from an order betweenone and two to a substantial higher order.

In the experiment carried out with TL, the gas velocity at whichflooding started was determined at an absolute pressure of 2 bar and asuperficial liquid velocity of 3 mm/s. The STL were tested at theconditions at which the TL showed starting of flooding at 2 bara and aliquid superficial velocity of 3 mm/s. At these conditions, the gasvelocity could be increased as much as 3.4 times before the STL showedthe onset of flooding. The use of STL, therefore, delayed reaching offlooding conditions substantially.

1. An elongate, shaped particle formed from a porous material comprisingthree protrusions each extending from and attached to a central positionaligned along the central longitudinal axis of the particle, thecross-section of the particle occupying the area encompassed by theouter edges of six outer circles around a central circle minus the areaoccupied by three alternating outer circles, wherein each of the sixouter circles is touching two neighbouring outer circles and whereinthree alternating outer circles are equidistant to the central circle,have the same diameter, and may be attached to the central circle. 2.The particle according to claim 1, wherein three alternating outercircles have a diameter in the range between 0.74 and 1.3 times thediameter of the central circle.
 3. The particle according to claim 2,wherein three alternating outer circles have the same diameter as thecentral circle.
 4. The particle according to claim 3, wherein threealternating outer circles are attached to the central circle.
 5. Theparticle according to claim 4, having a L/D ratio of at least
 2. 6. Theparticle according to claim 5, having a L/D ratio in the range between 2and
 5. 7. The particle according to claim 6, having a length in therange between 1 mm and 25 mm.
 8. The particle according to claim 7,which has been formed from alumina, silica, silica-alumina, magnesia,titania, zirconia, a synthetic or natural zeolite or mixtures of two ormore of these materials.
 9. The particle according to claim 8,containing a metal or a metal compound or both having catalyticactivity.
 10. The particle according to claim 9, containing a metal or ametal compound or both having hydroprocessing activity.
 11. The guardbed containing particles according to claim
 1. 12. The process forreducing fouling or the impact of fouling deposition in catalyst bedswhich comprises contacting a charge containing fouling material with alayer of particles according to claim
 1. 13. The process for theconversion of an organic charge comprising contacting the charge with acatalyst containing particles according to claim
 9. 14. The processaccording to claim 13, in which the conversion compriseshydrodesulphurisation of a hydrocarbonaceous feedstock.
 15. The processfor the production of middle distillates from synthesis gas in whichheavy paraffinic material produced from carbon monoxide and hydrogen issubjected to a hydrocracking process to produce middle distillates inthe presence of a catalyst containing particles according to claim 1,and which contain a metal or a metal compound possessing hydrocrackingactivity.
 16. The process for the conversion of hydrocarbons whencarried out under conditions of countercurrent gas-liquid flow in thepresence of particles according to claim
 1. 17. The particle accordingto claim 1, wherein three alternating outer circles are attached to thecentral circle.
 18. The particle according to claim 2, wherein threealternating outer circles are attached to the central circle.
 19. Theparticle according to claim 1, having a L/D ratio of at least
 2. 20. Theparticle according to claim 2, having a L/D ratio of at least
 2. 21. Theparticle according to claim 3, having a L/D ratio of at least
 2. 22. Theparticle according to claim 1, having a length in the range between 1 mmand 25 mm.
 23. The particle according to claim 2, having a length in therange between 1 mm and 25 mm.
 24. The particle according to claim 3,having a length in the range between 1 mm and 25 mm.
 25. The particleaccording to claim 4, having a length in the range between 1 mm and 25mm.
 26. The particle according to claim 5, having a length in the rangebetween 1 mm and 25 mm.
 27. The particle according to claim 1, which hasbeen formed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 28. The particle according to claim 2, which has beenformed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 29. The particle according to claim 3, which has beenformed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 30. The particle according to claim 4, which has beenformed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 31. The particle according to claim 5, which has beenformed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 32. The particle according to claim 6, which has beenformed from alumina, silica, silica-alumina, magnesia, titania,zirconia, a synthetic or natural zeolite or mixtures of two or more ofthese materials.
 33. The particle according to claim 1, containing ametal or a metal compound or both having catalytic activity.
 34. Theparticle according to claim 2, containing a metal or a metal compound orboth having catalytic activity.
 35. The particle according to claim 3,containing a metal or a metal compound or both having catalyticactivity.
 36. The particle according to claim 4, containing a metal or ametal compound or both having catalytic activity.
 37. The particleaccording to claim 5, containing a metal or a metal compound or bothhaving catalytic activity.
 38. The particle according to claim 6,containing a metal or a metal compound or both having catalyticactivity.
 39. The particle according to claim 7, containing a metal or ametal compound or both having catalytic activity.
 40. The process forreducing fouling or the impact of fouling deposition in catalyst bedswhich comprises contacting a charge containing fouling material with alayer of particles according to claim
 2. 41. The process for reducingfouling or the impact of fouling deposition in catalyst beds whichcomprises contacting a charge containing fouling material with a layerof particles according to claim
 3. 42. The process for reducing foulingor the impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 4. 43. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 5. 44. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 6. 45. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 7. 46. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 8. 47. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 9. 48. The process for reducing fouling orthe impact of fouling deposition in catalyst beds which comprisescontacting a charge containing fouling material with a layer ofparticles according to claim
 10. 49. The process for the conversion ofan organic charge comprising contacting the charge with a catalystcontaining particles according to claim
 10. 50. The process-for theproduction of middle distillates from synthesis gas in which heavyparaffinic material produced from carbon monoxide and hydrogen issubjected so a hydrocracking process to produce middle distillates inthe presence of a catalyst containing particles according to claim 2,and which contains a metal or a metal compound or both possessinghydrocracking activity.
 51. The process for the production of middledistillates from synthesis gas in which heavy paraffinic materialproduced from carbon monoxide and hydrogen is subjected to ahydrocracking process to produce middle distillates in the presence of acatalyst containing particles according to claim 3, and which contains ametal or a metal compound or both possessing hydrocracking activity. 52.The process for the production of middle distillates from synthesis gasin which heavy paraffinic material produced from carbon monoxide andhydrogen is subjected to a hydrocracking process to produce middledistillates in the presence of a catalyst containing particles accordingto claim 4, and which contains a metal or a metal compound or bothpossessing hydrocracking activity.
 53. The process for the production ofmiddle distillates from synthesis gas in which heavy paraffinic materialproduced from carbon monoxide and hydrogen is subjected to ahydrocracking process to produce middle distillates in the presence of acatalyst containing particles according to claim 5, and which contains ametal or a metal compound or both possessing hydrocracking activity. 54.A The process for the production of middle distillates from synthesisgas in which heavy paraffinic material produced from carbon monoxide andhydrogen is subjected to a hydrocracking process to produce middledistillates in the presence of a catalyst containing particles accordingto claim 6, and which contains a metal or a metal compound or bothpossessing hydrocracking activity.
 55. The process for the production ofmiddle distillates from synthesis gas in which heavy paraffinic materialproduced from carbon monoxide and hydrogen is subjected to ahydrocracking process to produce middle distillates in the presence of acatalyst containing particles according to claim 7, and which contains ametal or a metal compound or both possessing hydrocracking activity. 56.The process for the production of middle distillates from synthesis gasin which heavy paraffinic material produced from carbon monoxide andhydrogen is subjected to a hydrocracking process to produce middledistillates in the presence of a catalyst containing particles accordingto claim 8, and which contains a metal or a metal compound or bothpossessing hydrocracking activity.
 57. The process for the conversion ofhydrocarbons when carried out under conditions of countercurrentgas-liquid flow in the presence of particles according to claim
 2. 58.The process for the conversion of hydrocarbons when carried out underconditions of countercurrent gas-liquid flow in the presence ofparticles according to claim
 3. 59. The process for the conversion ofhydrocarbons when carried out under conditions of countercurrentgas-liquid flow in the presence of particles according to claim
 4. 60.The process for the conversion of hydrocarbons when carried out underconditions of countercurrent gas-liquid flow as the presence ofparticles according to claim
 5. 61. The process for the conversion ofhydrocarbons when carried out under conditions of countercurrentgas-liquid flow in the presence of particles according to claim
 6. 62.The process for the conversion of hydrocarbons when carried out underconditions of countercurrent gas-liquid flow in the presence ofparticles according to claim
 7. 63. The process for the conversion ofhydrocarbons when carried out under conditions of countercurrentgas-liquid flow in the presence of particles according to claim
 8. 64.The process for the conversion of hydrocarbons when carried out underconditions of countercurrent gas-liquid flow in the presence ofparticles according to claim
 9. 65. The process for the conversion ofhydrocarbons when carried out under conditions of countercurrentgas-liquid flow in the presence of particles according to claim 10.